Normalization unit 3

When we normalize a relationship, we decompose the relation. The decomposition should satisfy ........................................ , ..................................

Problems in Relational Data Model without normalization are :

• Anomalies

• Information Redundancy

• None of the above

"Constraint between two attributes or two sets of attributes."

The above statement is referring to :

• Functional Dependecies

• Transitive Dependencies

Which of the following statements fully describes data in 2NF:

• When any repeating fields have been removed and the table is given a primary key

• When all repeating entries of data are removed and the fields in each table are directly related to the primary key and no fields are present that are not related to each other

• When all the fields in each table are directly related to the primary key

Anomalies is Errors or inconsistence that may result when a user attempts to update a table that contains redundant data.

• True

• False

What is a foreign key?

• A unique identifier in a database

• A primary key of one table that appears in another table

• A field that should not be in a table and needs removing

THESE ARE THE TWO TERMINOLOGIES FOR ROW

• RECORD

• FIELD

• FILE

• TUPLE

SELECT * FROM employee WHERE salary>10000 AND dept_id=101;

Which of the following fields are displayed as output?

• Salary, dept_id

• Employee

• Salary

• All the field of employee relation

Drop table statement

• deletes the table structure only

• deletes the table structure along with the table data

• works whether or not referential integrity constraints would be violated

• is not an SQL statement

The main reason for normalizing the relations is removing these anomalies. Failure to eliminate anomalies leads to data redundancy and can cause data integrity and other problems as the database grows.

• True

• False